Amazon? eBay? Or a little of both? What exactly is Alibaba?

Alibaba is taking the investing world by storm as it prepares for its initial public offering. Analysts say it may be the largest tech IPO ever, making more money than Facebook's 2012 offering.

But what exactly is Alibaba? The Chinese tech titan is a giant online bazaar, with millions of merchants and businesses buying and selling just about anything you can imagine. By some measures, it's the world's biggest e-commerce site.

Brent Lewin | Bloomberg | Getty Images

It's been described as the Amazon and eBay of the East, but it's really both of them. "That's a fair assessment because last year it had sales of over $248 billion, which is more than those two companies combined," said Mike Prospero, reviews editor at Laptop Mag.

Alibaba is made up of three commerce sites, Taobao, Tmall and Alibaba.com.

Paying for goods on Alibaba is safe, according to Prospero, especially when using Alipay, which works much the same way as PayPal.

Americans can shop on Alibaba now, he said, but there is a pitfall the company and consumers still have to contend with, fake goods.

"One thing consumers do have to look out for though is that there are still a lot of counterfeit goods available on Alibaba's site. The company is taking some steps to counteract that but there are still plenty of fakes to be found there," said Prospero.